Cutter for key-seating machines.



Patented May 6, 1913.

T. G. FREDERICK.

APPLICATION FILED APR.9, 1912.

CUTTER FOR KEY SEATING MACHINES.

ATTORNEY I WITNESSES:

% )ffl Mm UNTT STATES PATENT CE.

TILGHMAN G. FREDERICK, OF BERNI-IARTS, PENNSYLVANIA, ASSIGNOR TO MITTS &MERRILL, OF SAGINAW, MICHIGAN, A CORPORATION OF MICHIGAN.

CUTTER FOR KEY-SEATING MACHINES.

To all whom it may concern.

Be it known that I, TILGHMAN G. FRED- ERICK, a citizen of the UnitedStates, residing at Bernharts, in the county of Berks and State ofPennsylvania, have invented certain new and useful Improvements inCutters for Key-Seating Machines; and I do hereby declare the followingto be a full, clear, and exact description of the invention, such aswill enable others skilled in the art to which it appertains to make anduse the same.

This invention is a cutter for key-seating machines and the improvementconsists in a cutter head having a removable knife, the head beingmounted on a vertically traveling bar such as is common in key-seatingmachines, but provided with means for securing the knife in the head sothat it can be readily removed and inserted and can be firmly heldagainst chattering or skew movement with relation to the head.

Vith these objects in view and certain others which will appear later inthe specifications, my invention consists in the devices described andclaimed and the equivalents thereof.

In the drawings, Figure 1 is a vertical section through the cutter headand knife taken on the line 0000 of Fig. 3; Fig. 2 is a similar verticalsection taken on the line q g of Fig. 3 and showing the upper end of acutter bar to which the head is at tached; Fig. 3 is a top plan view ofthe cutter head with the fastening bolts removed, showing in partcross-section the upper end of the cutter bar, the part section of thecutter bar being taken on the line 2-z of Fig. 2; Fig. 4 is a rear viewof the cutter head; Fig. 5 is a perspective view; and 6 is a perspectiveview of the knife; and Fig. 7 is a modified form of knife.

The cutter head consists in a metal block 1 adapted to be secured to acutter bar in any desired manner, as for illustration by a dove-tailedtenon 2 on its rear face, the tenon received in a corresponding mortise3 formed in the face of the cutter bar 4 which is of usual construction.A groove 5 eX- tends horizontally across the front face of the block 1and extends back into the block in a diagonally upward direction, and acentral vertical hole 10 is formed in the block, intersecting the groove5. A knife 6 is re- Specification of Letters Patent.

Application filed April 9, 1912.

Patented May 6, 1913.

Serial No. 689,652.

movably inserted in the groove 5 and has its cutting edge projectingbeyond the front of the block. The knife is provided with a centraldiagonally disposed threaded hole 12.

In assembling, the knife 6 is inserted in the groove 5 with its back 7bearing snugly against the block at the back of the groove. A cap screw15 having its lower end threaded is inserted in the hole 10, which isnot threaded, and is screwed into the threaded hole 12 of the blade sothat when the cap screw is tightened, it firmly holds the upper face ofthe groove 5. The screw 15 is also performs the additional function of atightperforms the addition function of a tightener to draw the knife 6rearwardly against the back of the groove 5.

Since there is a small amount of clearance between the threads of thescrew and the threads of the knife, and between the screw 15 and thehole 10, and since the knife is set at an angle with reference to thescrew, tightening the screw will draw the knife upward and rearward soas to seat it firmly against the back of the groove, while it also seatsthe upper face of the knife against the top of the groove. The knife isthus held firmly in contact with the metal of the block in alldirections that are opposed to the strain of the cut, thereby preventingchattering and skewing of the knife when in use.

My invention also provides means whereby the knife can be accuratelycentered with respect to the work. In cutting key-seats it is importantthat the middle point of the cutting edge of the knife lie on a radiusdrawn from the center of the bore of the hub or other article in whichthe key-seat is being cut, to the center line of the key-seat. This isnecessary in order that the key-seat in the hub may be square with thekeyseat of the shaft upon which the hub is to be keyed, and in orderthat the key ways in the hub and shaft may register. A slight lateraloff-set of the key-seat in the hub, due to the ends of the knife havingprojected unequally from the center line of the block, impairs theefficiency of the key and makes it difficult to fit. Care is thereforetaken in building key-seating machines to set the block 1 so that itshall be accurately centered with reference to the work. Hence itbecomes important that the knife 6 be provided with means by which itcan be accurately attached to the block so as to be properly centralwith reference to the work. To accomplish this purpose I provide twoholes 8, 8, extending vertically through the block, and preferablythread these holes from the upper surface of the block down to thegroove 5, as shown in Fig. 2, the lower ends 9 of the holes in the blockbeing of smaller diameter and not threaded. A pin 14 preferably threadedat its upper end and reduced in diameter at its lower end, as shown inFig. 2, is then inserted into each of the openings 8, 8, the lower endsof the pins passing through diagonally disposed holes 13 formed in theknife 6 and projecting into the holes 9 in the block below the knife.These pins insure that the knife will be properly central with referenceto the work, as above described, and also make it possible to useinterchangeable knives of various lengths, any one of which will beproperly centered.

In Fig. 7 I have illustrated a modified and, for some uses, a preferredform of knife which may be centered in the block without employing thepins 14. In this modifiedform of knife the threaded hole 12 is the sameas in Fig. 6, but projections 16, 16 are provided on one face of theknife, the projections being spaced apart a distance equal to the widthof the block so as to engage the side faces of the block when the knifeis slipped into the slot, thereby maintaining the knife in its centralposition.

Having described my invention, what I claim and desire to secure byLetters Patent, 1s:

1. A cutter head comprising a block, the

front of said block provided with a groove projecting diagonally upward,said block formed with a hole intersecting said groove; a knife receivedin said groove and projecting beyond the front of said block, said knifeformed with a diagonally disposed threaded opening; a clamping boltloosely received in the hole of said block and threaded at its lower endinto the threaded opening of said knife and adapted when tightened todraw said knife upwardly and rearwardly into close engagement with saidblock at the top and the back of said grooves; and means engaging saidblock and knife and adapted to maintain said knife in central positionwith respect to said block.

2. A cutter head comprising a block, the front of said block providedwith a groove projecting diagonally upward, said block formed with ahole intersecting said groove; a knife received in said groove andprojecting beyond the front of said block, said knife formed with adiagonally disposed threaded opening; a clamping bolt loosely receivedin the hole of said block and threaded at its lower end into thethreaded opening of said knife and adapted when tightened to draw saidknife upwardly and rearwardly into close engagement with said block atthe top and the back of said grooves; and pro-jec tions on said knifeengaging said block to maintain said knife in central position withrespect to said block.

In testimony whereof, I afliX my signature in presence of two witnesses.

TILGHMAN Gr. FREDERICK. Witnesses:

JOSEPH PREssER, THOMAS E. BROWN.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents, Washington, D. C.

